WARNING: This page is about a different car, the 2005 Chevrolet Optra5 and 2005 Chevrolet Optra. However, it is still accessible from the selected car via links, so may be relevant.
Fig 1: Locating Engraved VIN
Courtesy of GENERAL MOTORS CORP.
The vehicle identification number (VIN) is engraved in the top of the bulkhead.